Two-dimensional structure-embedded acoustic lenses based on periodic acoustic black holes
Abstract
Recent studies have introduced a new class of two-dimensional acoustic metamaterials whose dispersion and propagation properties result from the use of geometric inhomogeneities in the form of Acoustic Black Holes (ABH). The ABH is an element able to smoothly bend acoustic rays and slow down elastic bending waves, therefore providing a variety of unconventional dispersion and propagation properties that are typically observed in more complex multi-material and locally resonant designs. Our approach enables full integration of acoustic lenses in thin-walled structural elements while preserving the structural character. The lenses are capable of different high-level functionalities such as focusing, collimation, and negative refraction. Numerical and experimental results show that such structures exhibit broadband operating conditions that span both the metamaterial and the phononic range.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 11, 2017
- Source ID
- 10.1063/1.4998524
Entities
People
- Fabio Semperlotti
- Hongfei Zhu
Organizations
- Air Force Office of Scientific Research
- Purdue University
- University of Notre Dame